Direct Aldehyde Csp2 -H Functionalization through Visible-Light-Mediated Photoredox Catalysis
Minh Duy Vu1, Mrinmoy Das1, Xue-Wei Liu1
1Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore, 637371, Singapore.
Chemistry (Weinheim an Der Bergstrasse, Germany)
|October 24, 2017
Summary
Visible-light photoredox catalysis enables mild C-H activation of aldehydes, generating acyl radicals. These radicals efficiently form unsymmetrical ketones via alkene addition or nickel-catalyzed cross-coupling reactions.
Area of Science:
- Organic Chemistry
- Catalysis
- Synthetic Methodology
Background:
- Forming carbon-carbon bonds under mild conditions remains a significant challenge in synthetic chemistry.
- Selective C-H activation offers a direct pathway to generate reactive intermediates for bond formation.
- Visible-light photoredox catalysis has emerged as a powerful tool for mild organic transformations.
Purpose of the Study:
- To develop a mild and effective method for Csp2-H activation of aldehydes using visible-light dual photoredox organocatalysis.
- To generate nucleophilic acyl radicals from aldehydes.
- To demonstrate the utility of these acyl radicals in synthesizing unsymmetrical ketones.
Main Methods:
- Visible-light-mediated dual photoredox organocatalysis for Csp2-H activation of aldehydes.
- Generation of acyl radicals from aldehydes.
- Subsequent reactions of acyl radicals: addition to electrophilic alkenes and nickel-catalyzed cross-coupling.
Main Results:
- Successful Csp2-H activation of aldehydes under mild, visible-light conditions.
- Efficient generation of nucleophilic acyl radicals.
- Broad access to diverse unsymmetrical ketones through subsequent addition or cross-coupling reactions.
Conclusions:
- Visible-light dual photoredox organocatalysis provides a mild and effective strategy for aldehyde C-H activation.
- The generated acyl radicals are versatile intermediates for constructing unsymmetrical ketones.
- This methodology offers a rapid route to valuable organic building blocks containing ketone functionalities.
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